Sputum Smear-positive Patients Research Articles

Incidence and outcome of anti-tuberculosis drug-induced hepatotoxicity in tuberculosis inpatients

Based on the medical records and follow-up records of hospitalized patients who received anti-tuberculosis therapy in the Third People's Hospital of Zhenjiang in Jiangsu province from 2006 to 2012, we investigated the incidence and outcome of anti-tuberculosis drug induced hepatotoxicity(ATDH)and provided evidence for the prevention of ATDH. According to tuberculosis patients' medical information and liver function test records, ATDH patients were diagnosed according to the criteria of International Consensus Meeting and American Thoracic Society respectively, then the related factors and outcomes were analyzed. A total of 1 967 hospitalized tuberculosis patients were reviewed retrospectively, in which 1 403(71.3%)were men, 1 790(91.0%)were pulmonary tuberculosis patients, 1 528(77.8%)were patients receiving initiative treatment, 979(49.8%)were sputum smear-positive patients, and 1 297(65.9%)had other complicated diseases. According to the criterion of International Consensus Meeting, the incidence of ATDH was 16.5%, the median time of onset was 25 days. According to the criterion of American Thoracic Society, the incidence of ATDH was 8.3%, the median time of onset was 23 days. The incidence of ATDH was significantly higher in males and HRZE therapy group(P<0.05). Under the two liver criteria, 69.5% and 70.1% of the patients changed primary therapy respectively after ATDH occurred. 89.8% and 88.4% patients' liver function returned to normal range after changing or stopping therapy. According to two liver injury criteria, the incidences of ATDH were 16.5% and 8.3% in hospitalized tuberculosis patients respectively, and ATDH mainly occurred in the first month of anti-tuberculosis treatment. The monitoring of liver function should be strengthened in males and HRZE therapy group to reduce the incidence of ATDH.

Sputum smear microscopy result: a predictor for drug-resistant tuberculosis?

Until countries establish capacity for continuous surveillance systems, representative surveys of tuberculosis (TB) patients continue to improve our understanding of the burden of drug-resistant TB and help ensure appropriate allocation of resources. Although the available data are limited, the current recommendation of restricting surveys to sputum smear-positive patients is justified, given the greatly simplified logistics and only limited evidence in specific settings of an association between drug resistance and sputum smear status. Nonetheless, the relationship between drug resistance and sputum smear microscopy results may vary according to the setting and population under study. With the increasing availability and use of molecular diagnostics and the drive for universal drug susceptibility testing under the World Health Organization's End TB Strategy, substantially more data on drug resistance in the whole TB patient population should become available in the near future.

Digital PCR assay detection of circulating Mycobacterium tuberculosis DNA in pulmonary tuberculosis patient plasma

Nucleic acid amplification tests are a major diagnostic tool for pulmonary tuberculosis (PTB). Recently, digital PCR (dPCR) assay has improved sensitivity for the detection of small copy numbers of target molecules. The aim of this study is to explore the utility of dPCR for detecting Mycobacterium tuberculosis (MTB) DNA in PTB patient plasma. Total DNA was purified from plasma samples of newly diagnosed sputum smear-positive PTB patients. Copy numbers of MTB-specific genes in the samples were quantified with dPCR assays targeted for IS6110 or gyrB. A total of 33 PTB patients were enrolled. Significant differences between PTB patients and controls were observed in copy numbers of both targets: IS6110 mean±SD, 144.8±538.3 vs 0.44±0.49 (copies/20μL, p=0.004; Mann-Whitney U test) and gyrB mean±SD, 359.0±2116 vs 0.07±0.28 (copies/20μL, p=0.011; Mann-Whitney U test), respectively. This test had sensitivities of 65% or 29% and a specificity of 93% or 100% with the IS6110-targeted or gyrB-targeted assays, respectively. A dPCR assay successfully detected MTB DNA in PTB patient plasma. This minimally invasive and accurate method has potential to become an alternative diagnostic option.

Pattern of adverse drug reactions in new smear positive patients of pulmonary tuberculosis treated under directly observed treatment short course

Background: Directly observed treatment short course (DOTS), a combination therapy, drugs are administered for six to eight months in patients diagnosed with tuberculosis, increases the risk of adverse drug reactions. The objective of this study was to study the adverse drug reaction profile of new sputum smear positive (NSP) patients of pulmonary tuberculosis (PTB) treated under DOTS. A prospective observational study was carried out in Dr. RPGMC Kangra at Tanda, Himachal Pradesh, India over a period of six months. Methods: The study included 130 newly diagnosed TB patients on anti‑TB treatment under DOTS. A symptom based approach was followed for monitoring ADRs. The severity was assessed by Modified Hartwig scale and causality by WHO-UMC probability scale. Data was expressed as percentages for discrete variables using Microsoft excel. Results: Out of the total 130, 84 patients experienced ADRs with an overall incidence of 64.6%. 45 (34.6%) patients showed single ADR whereas 39 (30%) patients had two or more ADRs. Gastritis alone was present in 36 (27.8%) patients followed by itching 2 (1.5%), hypersensitivity 2 (1.5%), arthralgia 2 (1.5%), generalized weakness 2 (1.5%) and jaundice in 1 (0.8%) patients. Vomiting was present in 29 (22.2%) patients, neuropathy in 4 (3.1%) patients, arthralgia in 2(1.5%) patients, hypersensitivity, jaundice, itching and generalized weakness in 1 (0.8%) patient each. 21 (16.2%) patients experienced mild , 56 (43.1%) had moderate and only 7 (5.4%) had severe ADRs. All the ADRs were possible in nature. Conclusions: The incidence of ADRs was 64.6% and GI irritation was found to be most common ADR reported by 57.6% patients.

Genetic Structure and Drug Susceptibility Patterns of Mycobacterium tuberculosis Complex Strains Responsible of Human Pulmonary Tuberculosis in the Major Rearing Region in Cameroon.

Background. Cameroon this last decade continues to present a low contribution of M. africanum and M. bovis in human tuberculosis (TB), while M. bovis was prevalent in cattle but all these pieces of information only concerned West and Center regions. Methods. We carried out the first study in Adamaoua, one of the most rearing regions of Cameroon, on the genetic structure and drug susceptibility of the MTBC strains isolated from newly diagnosed sputum smear-positive patients aged 15 years and above. For that purpose, spoligotyping, a modified 15 standard MIRU/VNTR loci typing, and the proportion method were used. Results. Four hundred and thirty-seven MTBC isolates were analyzed by spoligotyping. Of these, 423 were identified as M. tuberculosis, within the Cameroon family being dominant with 278 (65.7%) isolates; twelve (2.75%) isolates were classified as M. africanum and two as M. bovis. MIRU/VNTR typing of the most prevalent sublineage (SIT 61) suggested that this lineage is not a unique clone as thought earlier but could constitute a group of strains implicated to different pocket of TB transmission. Only M. tuberculosis sublineages were associated with antituberculosis drug resistance. Conclusion. These results showed the weak contribution of M. africanum and M. bovis to human active pulmonary tuberculosis in Cameroon even in the rearing region.

Determinants of sputum conversion at two months of treatment under National Tuberculosis Programme, South India

Background: In India, Revised National Tuberculosis (TB) control programme (RNTCP) offers free diagnosis and treatment for TB, based on the Directly Observed Treatment Short (DOTS) course strategy. Under RNTCP, sputum conversion rate (SCR), at the end of 2 months of treatment is an important operational indicator, which is ideally expected to be 90%. Objectives: The objective of the present work was to investigate the factors associated with low SCR at the end of 2 months of treatment in Sira TB unit, Tumkur District, India. Material and Methods: It is a retrospective cohort study of all new sputum smear-positive patients registered in RNTCP in 2011. Data were retrieved from the TB register maintained at the District TB center. Chi-square and Student’s t-test were used for analysis of the study variables between patients who were sputum positive and sputum negative at the end of 2 months of treatment. Multivariate logistic regression was applied to determine the risk contributed by the variables towards non-conversion of sputum. Results: Of the 268 included patients, 66.7% patients were sputum negative. Patients aged ≥ 45 years were twice prone to be sputum positive (OR = 2.14) (P = 0.007). The odds of being sputum positive after 2 months of treatment was observed to be significantly high (OR = 7.12; 95% C.I. = 1.52–33.22; P = 0.01) for sputum grade 3+ at the time of diagnosis, respectively. Conclusion: Elderly patients with a high bacilli load should be advised and counselled well regarding adherence to treatment. Further, advice should be given on preventing spread of the disease by practising cough hygiene, as they are more infectious than other patients with less sputum-positive grade.

Pharmacokinetics of Isoniazid, Pyrazinamide, and Ethambutol in Newly Diagnosed Pulmonary TB Patients in Tanzania.

Exposure to lower-than-therapeutic levels of anti-tuberculosis drugs is likely to cause selection of resistant strains of Mycobacterium tuberculosis and treatment failure. The first-line anti-tuberculosis (TB) regimen consists of rifampicin, isoniazid, pyrazinamide, and ethambutol, and correct management reduces risk of TB relapse and development of drug resistance. In this study we aimed to investigate the effect of standard of care plus nutritional supplementation versus standard care on the pharmacokinetics of isoniazid, pyrazinamide and ethambutol among sputum smear positive TB patients with and without HIV. In a clinical trial in 100 Tanzanian TB patients, with or without HIV infection, drug concentrations were determined at 1 week and 2 months post initiation of anti-TB medication. Data was analysed using population pharmacokinetic modelling. The effect of body size was described using allometric scaling, and the effects of nutritional supplementation, HIV, age, sex, CD4+ count, weight-adjusted dose, NAT2 genotype, and time on TB treatment were investigated. The kinetics of all drugs was well characterised using first-order elimination and transit compartment absorption, with isoniazid and ethambutol described by two-compartment disposition models, and pyrazinamide by a one-compartment model. Patients with a slow NAT2 genotype had higher isoniazid exposure and a lower estimate of oral clearance (15.5 L/h) than rapid/intermediate NAT2 genotype (26.1 L/h). Pyrazinamide clearance had an estimated typical value of 3.32 L/h, and it was found to increase with time on treatment, with a 16.3% increase after the first 2 months of anti-TB treatment. The typical clearance of ethambutol was estimated to be 40.7 L/h, and was found to decrease with age, at a rate of 1.41% per year. Neither HIV status nor nutritional supplementations were found to affect the pharmacokinetics of these drugs in our cohort of patients.

Multidrug-Resistant Tuberculosis in Patients for Whom First-Line Treatment Failed, Mongolia, 2010-2011.

In Ulaanbaatar, Mongolia, multidrug-resistant tuberculosis (MDR TB) was diagnosed for more than a third of new sputum smear–positive tuberculosis patients for whom treatment had failed. This finding suggests a significant risk for community-acquired MDR TB and a need to make rapid molecular drug susceptibility testing available to more people.

Phenotypic and genotypic analysis of anti-tuberculosis drug resistance in Mycobacterium tuberculosis isolates in Myanmar.

BackgroundTuberculosis (TB) is one of the most serious health problems in Myanmar. Because TB drug resistance is associated with genetic mutation(s) relevant to responses to each drug, genotypic methods for detecting these mutations have been proposed to overcome the limitations of classic phenotypic drug susceptibility testing (DST). We explored the current estimates of drug-resistant TB and evaluated the usefulness of genotypic DST in Myanmar.MethodsWe determined the drug susceptibility of Mycobacterium tuberculosis isolated from sputum smear-positive patients with newly diagnosed pulmonary TB at two main TB centers in Myanmar during 2013 by using conventional phenotypic DST and the GenoType MTBDRplus assay (Hain Lifescience, Germany). Discrepant results were confirmed by sequencing the genes relevant to each type of resistance (rpoB for rifampicin; katG and inhA for isoniazid).ResultsOf 191 isolates, phenotypic DST showed that 27.7% (n=53) were resistant to at least one first-line drug and 20.9% (n=40) were resistant to two or more, including 18.3% (n=35) multidrug-resistant TB (MDR-TB) strains. Monoresistant strains accounted for 6.8% (n=13) of the samples. Genotypic assay of 189 isolates showed 17.5% (n=33) MDR-TB and 5.3% (n=10) isoniazid-monoresistant strains. Genotypic susceptibility results were 99.5% (n=188) concordant and agreed almost perfectly with phenotypic DST (kappa=0.99; 95% confidence interval 0.96-1.01).ConclusionsThe results highlight the burden of TB drug resistance and prove the usefulness of the genotypic DST in Myanmar.

Detection of Mycobacterium tuberculosis (MTB) in Fecal Specimens From Adults Diagnosed With Pulmonary Tuberculosis Using the Xpert MTB/Rifampicin Test.

Background. The Xpert Mycobacterium tuberculosis (MTB)/rifampicin (RIF) is a fully automated diagnostic test that allows for the detection of MTB including its RIF resistance. Although the test is used for the diagnosis of tuberculosis (TB) in sputum samples worldwide, studies using fecal specimens are scarce. We therefore evaluated the efficacy of the Xpert MTB/RIF test for detection of MTB in fecal specimens obtained from adult pulmonary TB patients, confirmed by culture and/or molecular diagnostic methods. Methods. We conducted a retrospective case-control study to provide proof-of-concept regarding the efficacy of the Xpert MTB/RIF test using fecal samples for diagnosing pulmonary TB via detection of MTB in adult patients (≥20 years) at the Fukujuji Hospital in Tokyo, Japan. Results. Fecal specimens were obtained from 56 active pulmonary TB patients (including 48 sputum smear-positive and 8 sputum smear-negative patients), 10 non-TB patients (including 4 Myocobacterium avium complex infections), and 27 healthy individuals who were exposed to active pulmonary TB patients. The sensitivity of the fecal Xpert MTB/RIF was 100% (81.7%-100%) for detection of MTB in specimens from sputum smear-positive (1+ to 3+) patients, 81.0% (58.1%-94.6%) in specimens from sputum smear scanty positive patients, and 50.0% (15.7%-84.3%) in specimens from sputum smear-negative patients. Meanwhile, each of the fecal specimens from the non-TB group was negative for MTB (specificity 100%; 95% confidence interval, 86.2-100). Conclusions. The fecal Xpert MTB/RIF test could detect MTB in a large proportion of smear-positive pulmonary TB patients, without frequent false-positive results at a TB referral hospital in Japan.

Transmission of Mycobacterium tuberculosis in China: a population-based molecular epidemiologic study.

Understanding the transmission of Mycobacterium tuberculosis is essential for the development of efficient tuberculosis control strategies. China has the second-largest tuberculosis burden in the world. Recent transmission and infection with M. tuberculosis, particularly drug-resistant strains, may account for many new tuberculosis cases. We performed a population-based molecular epidemiologic study of pulmonary tuberculosis in China during 1 July 2009 to 30 June 2012. We defined clusters as cases with identical variable number tandem repeat genotype patterns and identified the risk factors associated with clustering, by logistic regression. Relative transmission rates were estimated by the sputum smear status and drug susceptibility status of tuberculosis patients. Among 2274 culture-positive tuberculosis patients with genotyped isolates, there were 705 (31.0%) tuberculosis patients in 287 clusters. Multidrug-resistant (MDR) tuberculosis (adjusted odds ratio [aOR], 1.86; 95% confidence interval [CI], 1.25-2.63) and infection with a Beijing family strain (aOR, 1.56; 95% CI, 1.23-2.96) were associated with clustering. Eighty-four of 280 (30.0%) clusters had a putative source case that was sputum smear negative, and 30.6% of their secondary cases were attributed to transmission by sputum smear-negative patients. The relative transmission rate for sputum smear negative compared with sputum smear-positive patients was 0.89 (95% CI, .68-1.10), and was 1.51 (95% CI, 1.00-2.24) for MDR tuberculosis vs drug-susceptible tuberculosis. Recent transmission of M. tuberculosis, including MDR strains, contributes substantially to tuberculosis disease in China. Sputum smear-negative cases were responsible for at least 30% of the secondary cases. Interventions to reduce the transmission of M. tuberculosis should be implemented in China.

Trends for Tuberculosis Treatment Outcomes, New Sputum Smear Positive Patients in Kwekwe District, Zimbabwe, 2007-2011: A Cohort Analysis

Introduction: Tuberculosis remains a public health problem in Zimbabwe. Understanding the treatment outcomes is an important proxy indicator on the performance of the tuberculosis program. This study analyzed treatment outcomes of new sputum smear positive tuberculosis patients in Kwekwe district. Materials and Methods: A retrospective records review of new sputum smear positive tuberculosis patients registered in the district tuberculosis register in Kwekwe was conducted. Treatment outcomes were categorized according to the national tuberculosis control program and multivariate logistic regression model was used. P values less than 0.05 were considered statistically significant. Results: From a total of 1115 new sputum smear positive tuberculosis patients, cure rate ranged from 40.8% to 62.8% and death rate of patients decreased from 11 (8.0%) in 2007 to 17 (5.3%) in 2011 (p = 0.016). However, defaulter rate increased from 10 (7.3%) in 2007 to 30 (9.3%) in 2011. In multivariate logistic model, HIV positive tuberculosis patients were more likely to experience (adjusted RR = 1.84, 95% CI: 1.10 - 3.08) unfavorable treatment outcome when compared to negative counterparts. Urban residents were also at risk 1.91 (95% CI: 1.14 - 3.20) unfavorable outcome compared to rural residents. Conclusion: The cure rate was low (ranged from 40.8% to 62.8%) and the defaulter rate needed urgent attention. The district should conduct defaulter tracing and follow up.

Pattern of tuberculosis infection and adherence to Directly Observed Treatment Strategy at a teaching hospital in Nigeria

Background: Understanding the distribution pattern of tuberculosis infection as well as adherence to treatment guidelines could help to strengthen existing policy aimed at reducing morbidity associated with the disease. Aim: To assess the pattern of sputumsmear positive tuberculosis infection and adherence to Directly Observed Treatment Strategy (DOTS). Methods: This was a retrospective cohort study which utilized secondary data involving 210 sputum smear-positive tuberculosis patients with complete data out of 226 that underwent DOTS at LUTH from January 2008 to June 2011. Results: 66.2% of patients were HIV positive and 75.9% had pulmonary tuberculosis. The proximity of residence to the hospital was ≤25km for majority (65.7%) of the patients. 75.9% of the patients adhered to DOTS. Treatment outcomes included 72.5% cured, 8.6% dead and 12.4% defaulted. Median sputum conversion time was 67 (range: 63 ‐ 71) days. Patients who resided ≤25km to the hospital (65.7%) significantly adhered to treatment compared to those who lived >25km (31.6%). Also, patients who received family support significantly adhered to therapy (83.0%) com pared to those who did not (14.6%). Median conversion time was lower among those who adhered to treatment [58 (range: 54 ‐ 63) days] compared to those who did not [73 (range: 69 ‐ 77) days]. Conclusion: Majority of smear-positive tuberculosis infected pati ents were males and their level of adherence was high. Family support received was identified to influence adherence. Integration of family support with directly observed treatment strategy as well as location of treatment centers close to patients’ residence could enhance effectiveness of the strategy.

Five-year assessment of time of sputum smears conversion and outcome and risk factors of tuberculosis patients in central iran.

Objective. To evaluate risk factors which influence sputum smear conversion, outcome, and trends of conversion of sputum smear during 5 years and compare outcomes in patients with different regimens. Methods. In a retrospective cohort study, all patients with sputum smear positive tuberculosis were evaluated for comorbidities and demographic, microbiological, and therapeutic data and outcome. Smear examinations were performed at the beginning, at 2 months for CAT I, at 3 months for CAT II, at the end of second month of maintenance phase, and at the end of treatment. Results. This study enrolled 211 sputum smear positive patients, but 189 patients who completed the intensive phase of treatment were evaluated. Sputum smear of 158 patients converted at the end of intensive phase (83.6). Univariate analysis indicated that the risk of a persistent positive smear at the end of intensive phase was greater in diabetic patients ((odds 4.038, 95% CI 1.123–14.516) P = 0.033), and also a 3+bacillary load had risk of 2.933-fold ((95% CI 1.278–6.732) P = 0.011). Overall rate of unfavorable outcome was 20.9%. Factors associated with unfavorable outcome were age (P value 0.000), male gender (P value 0.027), diabetes (P value 0.000), and delayed conversion of sputum at the end of intensive phase (P value 0.000). Outcome for different regimens was not different significantly. Two specimens were isoniazid resistant. Conclusions. We suggest supervised treatment and care for diabetic patients and those with higher bacillary load. Paying attention to early diagnosis of tuberculosis in the elderly to reduce poor outcome and further measures to prevent transfer-out could improve the success rate.

Sputum volume predicts sputum mycobacterial load during the first 2 weeks of antituberculosis treatment.

Disease severity in patients with pulmonary tuberculosis is associated with mycobacterial sputum load. To ascertain whether reduced sputum production during treatment is a useful clinical sign of improvement, we analyzed the mycobacterial loads of 5,552 sputum samples collected from 439 newly diagnosed sputum smear-positive tuberculosis patients who participated in six 14-day studies of antituberculosis treatment. Sputum volumes were categorized as low (<6 ml), medium (6 to 10 ml), or large (>10 ml), and mycobacterial load was measured by the time to positivity in liquid culture and the CFU counts on solid culture. The association of sputum volume with mycobacterial load was estimated with multiple linear regression models adjusted for repeated measures. The predictor variables were sputum volume category, treatment day, specific study , and the interaction of sputum volume category and treatment day. Mycobacterial load was significantly associated only with the day on treatment and sputum volume, which tended to decrease with ongoing treatment. With the volume held constant, each day on treatment decreased the log CFU by 0.082 (P<0.001) and increased the time to positivity (TTP) by 1.04 h (P<0.001). From low to medium and from medium to large sputum volumes, the log CFU/ml increased by 0.265 (P<0.003) and 0.490 (P<0.001), respectively, and the TTP decreased by 1.17 h (P<0.001) and 1.30 h (P<0.001), respectively, for a given day of treatment. The variability of the sputum load measurements increased with the day of treatment and lower sputum volumes. The significant association of sputum volume and mycobacterial load validates decreasing sputum production as a clinical sign of improvement during early antituberculosis treatment.

Pulmonary tuberculosis patients with a vitamin D deficiency demonstrate low local expression of the antimicrobial peptide LL-37 but enhanced FoxP3+ regulatory T cells and IgG-secreting cells

Control of human tuberculosis (TB) requires induction and maintenance of both macrophage and T cell effector functions. We demonstrate that pulmonary TB patients with a vitamin D deficiency had significantly reduced local levels of the vitamin D-inducible antimicrobial peptide LL-37 in granulomatous lesions compared to distal parenchyma from the infected lung. Instead, TB lesions were abundant in CD3+ T cells and FoxP3+ regulatory T cells as well as IgG-secreting CD20+ B cells, particularly in sputum-smear positive patients with cavitary TB. Mycobacteria-specific serum IgG titers were also elevated in patients with active TB. An up-regulation of the B cell stimulatory cytokine IL-21 correlated with mRNA expression of CD20, total IgG and also IL-10 in the TB lesions. Altogether, vitamin D-deficient TB patients expressed a weak antimicrobial response but an IL-21 associated expansion of IgG-secreting B cells combined with a rise in FoxP3+ regulatory T cells at the local site of infection.

Molecular epidemiology of TB – Its impact on multidrug-resistant tuberculosis control in China

Aims and objectives The transmission pattern of drug resistant Mycobacterium tuberculosis (MTB) might vary due to the differences in geographic features, socio-economic development and TB epidemic in specific areas and populations. This might also reflect how effectively a TB control program would work. This study aimed to investigate the transmission pattern of drug resistant TB, especially multidrug-resistant (MDR)-TB, and to discuss its implications for an effective TB control program in rural China. Methods Applying a combination of conventional epidemiology with MIRU-VNTR-based genotyping and DNA sequencing, a descriptive cross-sectional study was performed in two Chinese rural counties: DQ, a long-term DOTS-covered county, and GY, where the DOTS program was launched 11 years later than DQ. Results In total, 238 bacteriologic confirmed pulmonary TB patients from DQ and 393 from GY diagnosed between 2008 and 2011 were recruited in the study. Of the 631 isolates, 220 (34.9%) were resistant to at least one anti-TB drug, including 95 (15.1%) simultaneously resistant to isoniazid and rifampicin or MDR, albeit with the similar distribution between DQ and GY (32/238 vs. 63/393; p, 0.378). The MIRU-VNTR genotyping revealed 35 isolates from DQ and 86 from GY exhibited 15 and 32 clustering patterns with four patterns shared between two counties. Compared with GY county, DQ had a significantly lower clustering proportion in MTB isolates susceptible to first-line drugs (25/167 vs. 46/198; p, 0.047) and total drug resistant TB isolates (12/71 vs. 44/149; p, 0.044), but a similar clustering proportion in MDR-TB isolates (8/32 vs. 18/63; p, 0.712). A significant higher clustering proportion was observed in the previously treated patients in both counties, but in the sputum smear-positive patients with cavitaries only in GY. Comparing the previously treated patients between the two counties, the proportion of MDR-TB and clustering proportion exhibited a similar distribution, while the average age of previously treated patients in DQ is significantly older than that in GY. Conclusions A lower proportion of recent transmissions was observed in the county with long-term DOTS implementation. However, DOTS itself might not have worked enough on blocking the recent transmission of MDR-TB. This observation suggests the urgent needs of implementing the Stop-TB strategies; in particular, accelerating the use of rapid molecular-based TB diagnosis and drug susceptibility testing, providing active case findings in a high risk population of MDR-TB and enhancing infection control in high MDR-TB burden countries.

Factors associated with tuberculosis among patients attending a treatment centre in Zaria, North-west Nigeria, 2010.

IntroductionTuberculosis remains a global public health problem. In 2011, tuberculosis incidence was 133 per 100,000 in Nigeria. In Nigeria, little is known about the factors associated with tuberculosis, especially in the northern part and only few studies have characterized the Mycobacterium species that cause tuberculosis infection in humans. This study determined factors associated with tuberculosis and identified Mycobacterium species causing human tuberculosis in North-West, Nigeria.MethodsWe conducted a hospital based case control study between April and July 2010 in Zaria. Cases were newly diagnosed sputum smear-positive tuberculosis patients >15 years while controls were patients >15 years attending the hospital for other reasons but were negative for tuber-culosis. We used a structured questionnaire to obtain information on demographics, knowledge of transmission of tuberculosis, and exposure to some factors. We preformed descriptive, bivariate and backward elimination logistic regression. Sputa from cases were analyzed by multiplex polymerase chain reaction (PCR) based on genomic regions of difference.ResultsThe mean ages of the cases and controls were 36, standard deviation (SD) 9.0 and 36, SD 9.7 respectively. Only 10 (9.8%) and nine (8.8%) of cases and controls respectively had a good knowledge of the transmission of tuberculosis. Contact with a tuberculosis patient (adjusted odds ratio (AOR) 12.3, 95% confidence interval (CI) 5.2-28.8), consumption of unpasteurized milk (AOR 6.4, CI 2.4-17.2), keeping pets (AOR 5.6, CI 2.3-13.7), associating closely with cattle (AOR 5.6, CI 1.3-6.8), and overcrowding (AOR 4.8, CI 1.8-13.1) were significantly associated with tuberculosis. Of the 102 sputa analyzed, 91 (89%) were M. tuberculosis, 8 (7.8%) were M africanum.ConclusionWe identified possible opportunities for intervention to limit the spread of tuberculosis. We recommend that the Nigeria tuberculosis control program consider some of these factors as a way to mitigate the spread of tuberculosis in Nigeria.

Profile of tuberculosis patients with delayed sputum smear conversion in the Pacific island of Vanuatu.

National tuberculosis control programme, Vanuatu. To assess tuberculosis (TB) trends, characterise sputum smear-positive patients with non-conversion at 2 months and assess their treatment outcomes. Evaluation of programme data over a 9-year period (2004-2012), comparing 2-month sputum non-converters (delayed converters) with sputum smear converters diagnosed in 2011 and 2012. Annual TB case numbers were similar over the study period, with an average TB notification rate of 58 per 100 000 population. Of 417 sputum smear-positive cases, 74 (18%) were delayed converters. Delayed converters were more likely than converters (88% vs. 79%) to have had high pre-treatment sputum smear grades (OR 2.5, 95%CI 0.97-6.45). Among delayed converters, treatment adherence was high (99% good adherence), outcomes were generally good (90% treatment success, 85% cure, 4% treatment failure) and no drug resistance was detected. Deaths were unexpectedly common among converters (11/80, 14%), with significantly more deaths in Tafea than in Shefa Province (7/58 vs. 2/80, OR 5.35, 95%CI 1.07-26.79). Tafea Province also had the greatest number of delayed converters (30/74, 40.5%) and the highest TB incidence rate. Delayed sputum conversion was relatively uncommon, and was not associated with adverse outcomes or drug resistance. Regional differences require further investigation to better understand local factors that may compromise patient management.

Tuberculosis management time: an alternative parameter for measuring the tuberculosis infectious pool

To demonstrate the application of TB management time as an alternative parameter to estimate the size of the tuberculosis infectious pool in West Gojjam Zone of Amhara Region, Ethiopia. In this study, we used the TB management time, i.e. the number of days from start of cough until start of treatment, to determine the infectious period. Patients with sputum smear-positive and smear-negative pulmonary TB, retreatment and an estimated number of undetected cases were included. The infectious pool was then estimated as the annual number of infectious person days in a defined population. The TB management time of presently undiagnosed TB cases and sputum smear-positive patients contributed significantly to the infectious pool with 151,840 and 128,750 infectious person days per year, respectively. The total infectious pool including sputum smear-negative TB cases and retreatment patients in the study area was estimated at 325,410 person days or 15,447 person days per 100,000 population during the study year. Recording TB management time may be used to estimate the infectious pool of TB and to monitor programme performance in the community.